Large-Area Flexible Electrochromic Devices with High-Performance and Low-Power Consumption Enabled by Hydroxyhexyl Viologen-Substituted Polyhedral Oligomeric Silsesquioxane

• DOI: 10.1021/acssuschemeng.3c00381
• Publication Date: 2023-03-26T19:49:51Z
• Authors: Fayong Sun; Joo Hee Eom; Do Yeon Kim; Gaurav K. Pande; Hyejin Ju; Han Gi Chae; Jong S. Park
• Keywords: Silsesquioxane; Electrochromic devices; Polyvinyl Butyral; Viologen

In this work, we prepared octa-hydroxyhexyl viologen-substituted polyhedral oligomeric silsesquioxane (OHHV-POSS) as an organic–inorganic composite material applicable for large-area flexible electrochromic devices (FECDs). The hybrid structure supported by the POSS cage and enhanced interaction between hydroxyl end-groups lithium salts can effectively increase ionic conductivity of ion gel films, thereby improving performance capabilities. Homogeneous was obtained with polyvinyl butyral a salt, outstanding properties were observed during device operations. FECDs various sizes fabricated systematic evaluation, up to 22.5 × 19.5 cm2 successfully constructed using simple doctor blade coating method. achieved large transmittance difference 70.0% at 604 nm, fast switching times 21.1 18.0 s, high coloration efficiency 260.61 cm2/C, long-term cycling stability 300 cycles, low power consumption about 250 μW/cm2. Furthermore, maintained stably in application tests heat insulation storage, UV resistance, mechanical stability. High OHHV-POSS prove suitable FECDs, suggesting promising potential smart windows, wristbands, eyewear products.